of Organic Elementary Analysis. 159 
After the combustion, the chlorid, together with the excess 
mi abe is extracted from the asbestos by means of dilute nitric 
aci 
in the analysis of sulphur compounds, 
I. Experiments with Oxyd of Lead and with Oxyd 
of Copper, placed in the anterior end of the com- 
bustion tube, as absorbents of Chlorine in the 
analysis of substances difficulily combustible. 
The substance selected for analysis, as a 
test of the process for that class of bodies 
in Gerhardt’s Zraité de Chimie. When the ff 
usual tests were applied, no impurity could 
be detected. 
viment 1,—A mixture of oxyd of lead and asbestos was 
placed in the anterior end of the combustion tube, between 
c and d, fig. 2, as previously described. As chlorid of lead was 
supposed to bear a pretty high temperature, without volatiliza- 
tion or decomposition, the use of the air-bath was omitted in this 
experiment, and the oxyd gently heated with a small flame from 
ée combustion furnace. The combustion had not proceeded 
far when it became apparent, from deposition of minute drops of 
liquid on the sides of the vacant part of the tube,—from 6 toc, 
fig. 2,—that the combustion of the chloloform was incomplete, 
although no doubt could exist as to the presence of an excess of 
oxygen. This deposit of liquid, which, as already stated, was 
supposed to be a chlorid of carbon, was found to be difficultly 
volatile, suffering partial decomposition, and leaving on the tube 
a brown deposit, which was not entirely removed by ignition in 
a stream of oxygen. The high temperature employed to burn 
off this deposit occasioned excessive heating of the posterior end 
of the mixture of lead oxyd and asbestos; and this may have 
n the cause, to some extent, of the excess in the determina- 
tions of carbon and hydrogen, although subsequent analyses indi- 
cate that the sample of chloroform under examination contained 
a larger percentage of these elements—particularly of the latter 
—than belongs to pure chloroform. This experiment gave 11°47. 
per cent of carbon, and 1:87 per cent of hydrogen. Theor. 
